I've been watching this with interest. So have 70 some odd others. It is starting to grow whiskers, with no takers. So I went to your rig's parts catalog http://www.winnebagoind.com/service/...07/7wpg38j.pdf
Yep, no significant difference is our (your and ours) door design. With that, I would suggest you remove the inner door panel. Secured by sheet metal screws a few inches apart all around the perimeter. Likely some around your latching mechanism , too.
I've removed/replaced ours several times. Once out of curiosity, twice working on the latch.
With the inner panel off, you can remove your wee beastie, find and correct its entry point.
Fair Winds and Following Seas